Jar



Dec. 21, 1937. la,A 1 SHANNON JAR Filed July l5, 1958 Patented Dec. 2l, 1937 unirse STATES PATENT OFFE Application July 13,

4 Claims.

This invention relates to a jar.

An object of the invention is to provide a jar adapted to be connected into an operating string of pipe which, in turn, may be connected 5y to the pipe or other object stuck in a well bore and whereby the stuck pipe may be vibrated or jarred and thus more readily released and removed from the well bore.

As is well known pipe often becomes stuck in a well bore vand in such a case it is common practice to lower a grapple attached to an operating string into the well and to engage the stuck pipe to pull the same from the well. Often times the pipe is so tightly stuck that it can not be pulled from the well and in such case it is advantageous to connect a jar into the operating string and by operation of which the stuck pipe may be vibrated or jarred and thereby released.

The invention herein described comprises a novel type of jar for the purpose herein indicated. y

It is another object of the invention to provide a jar that may be operated irrespective of the tension on the operating string.

It is a further object of the invention to provide a jar of the character described that can be controlled by the application of fluid under pressure exerted through the operating string by a pump at the ground surface.

It is still a further object of the invention to providesJ jar of the character described that is of such construction that it may be readily con.

nected into the operating string and lowered into the well and that may be operated by the application of iiuid under pressure.

With the above and other objects in view the invention has particular relation to certain novel features of construction, loperation and arrangement of parts, an example of which is given in this specication and illustrated inthe accompanying drawing wherein:

Figure l shows a vertical sectional view of the jar, shown in released vposition with the parts in the position they will occupy upon an impact stroke of the jar. y

Figure 2 shows a vertical sectional view of the jar with the impact member locked in inactive position.

Figure 3 shows a fragmentary vertical sectional view, showing the parts in position to be released to effect an imp-act stroke.

Figure 4 shows a cross sectional View taken on the line ll-fl of Figure 2, and

Figure 5 shows a diagrammatic view illustrat- 1936, serial No. 90,333

(o1. ass-27) i ing the jar connected into the operating string with the grapple connected to the stuck pipe.

Referring now more particularly to the drawing wherein like numerals of reference designate the same parts in each of the gures, the numeral 5 l designates a tubular housing to the lower end of which a reducing nipple 2 is attached, the housing and nipple being separated by a transverse partition 3.

The lower end of the nipple terminates in an outwardly threaded pin 4 which may be screwed into a length of tubing 5to which any conventional type of grapple 6 may be attached. This grapple is of well known construction and is of the releasable type and may be readily engaged withor relieved from the stuck pipe l.

Connected to the partition 3 and extending through it there is a lower cylinder 8 which is provided with the upper ports 9 spaced lapart above the partition and the lower ports I0 im- 20 mediately beneath said partition. The upper end of the cylinder 8 is closed except for the central bearing Il through which the stem l2 works. 'I'he upper end lli of the stem is tapered and attached to the lower end of the stem there 25 is a plunger M. A plug l5 closes the lower end of the cylinder and between said plug and the plunger Hl there is a coil'spring i6 which normally holds the plunger elevated as shown in Figure 2. The lower end of the cylinder is provided with a vent l1.

Pivotally mounted on and upstanding from the upper end of the cylinder are the oppositely arranged complemental links i8 whose upper ends are hemispherical in shape forming the complemental outwardly curved bosses lil, i9. The numeral 2li designates an operating string of pipe whose lower end is connected to the upper end of the tubular shank 2l. Throughout the major portion oi its length this shank is polygonal in cross section, said polygonal portion working through a correspondingly shaped bearing 22 in the sectional gland 23 which is screwed into and forms a closure for the upper end of lthe housing i. This gland is pinned in place by the pins 24 and contains the packing 25 which forms a close t between the gland and the shank 2|. The lower end of the gland has the radial grooves 2S as more clearly shown in Figures 1 and 2.

Within and spaced from the housing l and attached to the lower end of the shank 2l there is the upper cylinder 2l whose upper end is closed and whose lower end is open. This cylinder has an annular impact face 28 located at its upper end. The operating string 26 and shank 2| are .55

tubular and the lower end of the shank has the radial ducts 29 which register with the grooves 26, when the cylinder 21 is in its upper position. Y

Fitted snugly within the cylinder 21 there is a piston 30 which is supported on a coil spring 3| and the lower end of this spring surrounds the lower cylinder 8 and is supported on he partition 3. This spring 3| is not indispensa le.

The upper end of the piston 30 is formed with an annular impact face 32 arranged opposite the impact face 23. The lower' end of the piston 30 is formed with a socket 33 positioned to receive and interlock with the bosses I9, I9 when said Y I4 not being subjected to the pump pressure will be elevated by the spring I6. At this time the stem I2 will be in its elevated position and the links I8 will be in their outer position as shown in Figure 2 but the piston 30 will be in its upper position as shown in Figure 1. The pump may be now started and liquid under pressure will be forced down through the operating string and the shank 2l and'out through the ducts 29 in the grooves 2S and will pass on downwardly through the upper ports 9 and force the plunger i4 downwardly to clear the lower ports IB, the liquid beneath the plunger being relieved through the vent I1 Vand the spring I6 being placed under compression. The tapering portion I3 'of the stem I2 will thereby be withdrawn from between the links I8 and they will fall inwardly into the position shown in Figure 1. The operating string 2Q may now be lowered forcing the upper cylinder 21 downwardly until the bosses I9 are received by the socket 33 and the pump pressure again relieved, whereupon the spring I6 will elevate the plunger rod I 2, forcing the links I 8 apart as shown in Figure 2 and thus locking the piston 3Q in its lower position as shown in Figure 3. The operating string 2B may now be pulled upwardly withdrawing the cylinder 21 into its upper position as shown in Figure 3 thus creating a vacuum in said upper cylinder. The pump may then be again started forcing theY plunger I4 downwardly, as before, and withdrawing the upper end of the stem I2 from between the links i8, permitting said links to move inwardly and releasing the piston 3D. When the piston 30 is moved downwardly the springV 3l is placed under compression as shown in Figures 2 and 3 and upon release of the piston 3i! the vacuum above it, combined with the pressure of the spring 3I beneath it, will Cause said piston 30 to move upwardly at high speed, causing the impact face 32 to strike the opposing face 28 violently. At this time the operating string 20 may be under any desired tension so as to exert a constant upward pull on the stuck pipe and the jar incident to the impact will, in most cases, be eiective to release or assist in releasing the stuckpipe. The operationmay be repeated as often as necessary in order to completely release the Vstuck pipe 1.

While being so lowered the pump will be stopped and the plunger The drawing and description disclose what are now considered to be preferred forms of the invention by way of illustration only while the broad principle of the invention will be defined by the appended claims.

What I claim is:

l. A jar comprising a housing, a grapple attached to the housing, a cylinder in the housing having an impact abutment, a piston Vin the cylinder having an impact face opposite said abutment, means on the housing and piston adapted to interlock, said cylinder and piston being simultaneously movable into one position to cause the interengagement of said interlocking means to hold the piston stationary in the housing, said cylinder being movable independent of the piston to another position to cause a vacuum to be created in said cylinder and means arranged to be controlled by pressure fluid and adapted to release said interlocking means whereby to release the piston to permit said impact face to strike against said abutment.

2. A jar comprising a housing, means for connecting the housing to a grapple, an operating string associated with the housing, a lower cylinder in the housing, Y a plunger yieldingly mounted in said lower cylinder, an upper cylinder in the housing connected to the operating string, a piston in the upper housing, means on the lower cylinder engageable with the piston, means on the plunger normally operative to maintain such engagement, said piston and upper cylinder having opposing impact faces, said jar having a passageway therethrough for iuid pressure and said plunger being operable by said pressure torelease said engaging means.

3. A jar comprising a housing, grappling means connected to the housing, a cylinder-in the housing, an operating string operatively connected with the housing and to which the cylinder is attached, a piston in the cylinder, said cylinder and piston having opposing impact faces, a locking device engageable with the piston, said cylinder and piston being simultaneously movable to position to engage the piston with the locking device and the cylinder being movable to another position to create a vacuum within the cylinder and means arranged to be operated by uid under pressure, exerted through the operating string, to release the locking device from the piston.

4. A jar comprising a housing, grappling vmeans connected to the housing, a cylinder in the housing, an operatingV string operatively connected with the housing and to which the cylinder is attached, a piston in the cylinder, said cylinder and piston having opposing impact faces, a locking device engageable with the piston, said cylinder and piston being simultaneously movable Yto position to engage the pist-on with the locking deinto contact with the impact face 'of said cylinder.

BAKER L. SHANNON. 

